São Tomé Day is a public holiday observed in São Tomé and Príncipe every December 21. This day commemorates the discovery of the island of São Tomé by Portuguese navigators Pêro Escobar and João de Santarém around 1470, who arrived on the island on the feast day of Thomas the Apostle. The island was named São Tomé in honor of the saint and was uninhabited prior to the Portuguese arrival. The first successful settlement was established by Álvaro Caminha in 1493, although attracting settlers was challenging, leading to the importation of slaves for sugar plantations. Despite gaining independence from Portugal in 1975, the islanders continue to celebrate the anniversary of the island's discovery. Festive events and activities mark the occasion, and as a national holiday, government offices, educational institutions, and most businesses are closed for the day.